Improvement in screw-piling



etnica ,etang CHARLES H. PARKER, OF BOSTON, MASSACHUSETTS.

Letters Patent No. 101,379, dated March 29, 1870.

IMPROVEMENT IN SCREW-FILING.

The Schedule referred to in these Lettera Patent and making part of the same.

I, CHARLES H. PARKER, of Boston, county of Suffolk and State of Massachusetts, have invented certain Improvements in Hollow Screw-Piling, of which the following is a full and exact description, reference being had to the accompanying drawings and to the letters of reference marked thereon.

The object of my invention is to lift the mud, clay, sand, or other material into which the pile is being sunk away from the bottom edge of the pile, in order tofacilitate the descent of the pile.

Figure 1 is a side elevation of a pile embodying my invention. A

Figure 2 is a plan .of the same.

Figure 3 is avertical transverse section of the same.

Similar letters on different gures refer to same parts.

P is the pile, with its usual external worm or screw A.

In addition to the external worm or screw A, I have added an internal one,B. This internal screw is made with a greater pitch than the external. It operates upon the principle of the auger, lifting the mud, clay, sand, or other material into which the pile is being sunk away from the bottom and inner edge of the hollow pile, and this permits its easier descent by the action of the external screw.

What I claim as my-invent-ion, and desire to secure Letters Patent upon, is-

The hollow screw-pile P, constructed with an external screw, A, and an internal screw, B, which has a greater pitch than the external screw, in the manner and for the purpose described.

CHAS. H. PARKER.

ritnessesz CADWALLADER CURRY, WM. A. BLODGETT. 

